Electric switch



D@a 23, 1952 l.. J. KARL 2,623,142v

' ELECTRIC SWITCH Filed July 7 1950 ll "E /l 29 6 z 7 /Zf f j PatentedDec. 23, 1952 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to electrical switches of the snap-action type andhas for its primary object the provision of such a device which has aminimum of working parts.

A still further object of my invention is the provision of a device ofthe class described, which is positive in its action, which is easy tooperate, and which has great durability.

The above and still further objects and advantages of my invention willbecome apparent from the following detailed specication, appendedclaims, and attached drawings.

Refering to the drawings, wherein like characters indicate like partsthroughout the several views:

Fig. l is a view partly in vertical section and partly in side elevationof my novel switch;

Fig. 2 is a view corresponding to Fig. 1 but showing a differentarrangement of some of the parts thereof, and some parts being brokenaway;

Fig. 3 is a view in plan of the structure of Fig. 2;

Fig. 4 is a View corresponding to Fig. l but showing a slightly modifiedform of my invention;

Fig. 5 is a view in transverse section taken on the line 5-5 of Fig. 4;and

Fig. 6 is a fragmentary view corresponding to Fig. l, but showing astill further modified form of my invention.

Referring with greater particularity to the drawings, and, morespecifically, to Figs. 1-3 thereof, the numeral I indicates, in itsentirely, a switch housing having spaced front and rear walls 2 and 3respectively and side walls 4. Together, the walls 2, 3, and 4 define achamber 5. Front wall 2 is shown as being provided with a switcharm-receiving aperture or recess 6 which defines a generally circularinwardly-facing seat I concentric with the aperture 6. A switch arm 8works through the aperture IIi with clearance for limited rockingmovements in planes intersecting the axis of the seat 'I. At its innerend, the switch arm 8 is provided with an enlarged or expanded headportions. Y As shown, head 9 provides a generally circular seat Il)kadapted to seat against the seat 'I in the wall 2 of the housing whenthe switch arm is aligned with the axis of said seat 1. A coilcompression spring I I, having one end seated against the rear wall 3 ofthe housing in axial alignment with said front wall seat 1, has itsother end seated against and secured to an axial portion of the switcharm inwardly spaced from the seat I0 thereof. It will be noted that, inthe structure shown, the switch arm 8 is tiltable in all directionsradially of its axis, although this is not an essential limitation tothe invention.

As shown, the front wall 2 is provided with an annular fulcrum shoulderI2 concentric with and inwardly-spaced from, and of greater diameterthan, the wall seat l. Likewise, the head 9 is provided with an annularfulcrum shoulder I3 which cooperates with the fulcrum shoulder I2 undertilting movements of the switch arm 8.

Spring Il, in the structure of Figs. 1 3, forms a part of an electricallead I4, which, at its lower end, extends through the wall 4 andterminates in a connector I5. At its upper end, the lead I4 is shown asextending generally axially through the body 9, as indicated at I6, andterminates in an annular contact element I1. Preferably and as shown,the contact element I'I is raised from the plane of the surface of theconical seat I0. A cooperating contact element I8 is mounted on the seat1 and is disposed so as to have circuitclosing engagement with thecontact element I7 when the switch arm 8 is axially disposed withrespect to the aperture 6, as shown in Fig. l. An electrical lead I9extends radially outwardly from the contact element I1 and terminates ina screw-equipped connector 25 laterally outwardly of the adjacent sidewall 4.

Spring II tends to yieldingly maintain the switch arm 8, either in theseated position approximately perpendicular to the face of the frontwall as in Fig. l, whereby to close the circuit through the leads I4 andI9, or in the relatively tilted position with respect thereto, as shownin Fig. 2, wherein the contact elements I'I and I8 are separated wherebyto break the circuit. It will be noted, that, when the switch arm 8 istilted, the fulcrum shoulder I2 oft the front wall 2 is engaged by theannular fulcrum shoulder I3 of the head 9 to provide an axis of tippingmovement thereof. Under tilting movements of the switch arm 8, theextreme lower end of the head 9 moves beyond dead center relationshipwith respect to the lower end of the spring II, whereupon spring II willtend to further tilt the switch arm 8 and head 9 toward their positionof Fig. 2. Circuit-opening tilting movement of the switch arm 8 and head9 is limited by engagement of the upper iiat surface of the head 9radially outwardly of the annular fulcrum I3 thereof with the innersurface of the front wall 2 radially outwardly of the fulcrum shoulderI2. As shown in Fig. 2, this movement may be also limited by engagementof the switch arm t with a side wall portion of the aperture 6.

In the modified form of the invention shown in Figs. l and 5, thestructure, except for the disposition of the contact elements andcircuit leads, is identical to that of Figs. 1-3 inclusive; and partsidentical to those of Figs. 1-3 inclusive are given the same numeralswith prime marks added. In this embodiment of the invention, a pair ofopposed segmental contact elements 2l and 22 are mounted in spacedrelationship on the seat 1 and are connected to laterallyoutwardly-extending electrical leads 23 and 24 respectively whichterminate in screw-equipped connectors 25 and 2t on opposite sides ofthe housing adjacent the walls li' thereof. The contact surfaces of theelements 2l and 22 are adapted to make electrical circuit-closingconnection with the contact surface of an annular contact element 2!when the switch arm 6 is moved to its position axially of the aperture6. The circuit is broken by tipping the switch arm 8 in any desireddirection radially of the axis of the aperture the fulcrurn portion i3engaging the fulcrurn shoulder i2' in exactly the saine manner as thatof Fig. l-B inclusive.

In the modified form` illustrated in Fig. 6, a front wall section 2 isshown as having mounted on the inner wall thereof, radially outwardly ofthe fulcrurn shoulder l2", an annular contact element 28. An electricallead 2i) has one end secured to the contact element 23 and projectslaterally outwardly of the front wall 2", terminating in ascrew-equipped connector Bil. The enlarged head 9 of the switch arm iiis provided on its upper fiat surface radially outwardly of the annularfulcrum it thereof with an annular contact element 3i, the upper contactsurface thereof being adapted to malte circuit-closing connections withthe contact surface of the cooperating contact element 23 when theswitch arm il" is moved in a direction radially outwardly of the axis ofthe aperture f5". The circuit lead 32 is connected at one end to theannular Contact element 3l and extends downwardly through the enlargedhead s, its other end being connected to a coil compression spring I l.Although not shown, it may be assumed that the lower end of the spring li is connected to a lead and connector similar to that shown in Figs. 1and 2.

My invention has heen thoroughly tested and :found to be completelysatisfactory for the accomplishment of the above objects; and, while Ihave shown and described a preferred embodiment and two modifications ofmy novel switch construction, it will be understood that the same iscapable of further modification, as to construction and arrangement ofparts, without departure from the spirit and scope of the invention asdefined in the claims.

What I claim is:

l. In a switch of the class described, a switch housing having spacedfront and rear walls, the front wall being provided with a switcharm-receiving aperture and defining a generally circular inwardly-facingseat concentric with said aperture, a switch arm working through saidaperture with clearance for limited rocking movements in planesintersecting the axis of said seat and having an expanded head portionproviding a generally circular seat adapted to seat against the seat ofthe front housing wall when the switch arm is aligned with the axis ofthe housing wall seat, a compression spring having one end seatedagainst the rear wall of the housing in axial alignment with said frontwall seat having its other end seated against an axial portion of the.switch arm inwardly-spaced from the seat thereof, whereby the springwill yieldingly maintain the switch arm either in a position of coaxialalignment with the axis of the wall seat or in a relatively tiltedposition with` respect to the wall seat axis, the front wall and switcharm head having cooperating contact areas that are engaged in one ofsaid switch arm positions, said front wall having opposite fulcrumshoulder portions adjacent opposite inner marginal edges of the seatthereof, and cooperating shoulder portions on the switch arm forengagement with the wall shoulder portions under tilting movements ofthe switch arm.

2. In a switch of the class described, a switch housing having spacedfront and rear walls, the front wall being provided with a switcharm-receiving aperture and defining inwardly-facing seat portionsadjacent opposite marginal portions of the aperture, said switch armworking through said aperture with clearance for limited rockingmovements in a plane intersecting the center of the aperture and havingan expanded head portion providing a seat for engagement with the `seatportions of the front housing wall when the switch arm is approximatelyperpendicular to the outer surface of the front wall, and a compressionspring having one end seated against the rear wall of the housing at apoint inwardlyspaced from the inner end of the switch arm but in axialalignment with the switch `arm when the latter is approximatelyperpendicular to the outer surface of the front wall and having itsother end anchored to the inner end of said switch arm, whereby thespring will yieldingly maintain the switch arm either in a seatedposition approximately perpendicular to the outer face of the front wallor in a relatively tilted position with respect to the outer surface ofthe front wall, the front wall and switch arm having cooperating contactareas that are engaged in one of said switch arm positions, said frontwall being provided with an annular fulcrum shoulder portion concentricwith and inwardly-spaced from and of greater diameter than the wallseat, and a cooperating fulcrum shoulder on the switch arm for fulcrumengagement with the wall shoulder under tilting movements of the switcharm.

3. In a switch of the class described, a switch housing having spacedfront and rear Walls, the front wall being provided with a switchIarm-receiving aperture and defining a generally circularinwardly-facing seat concentric with said aperture, a switch arm working`through said aperture with clearance for limited rocking movements inplanes intersecting the axis of said seat and having an expanded headportion providing a generally circular seat adapted to seat against theseat of the front housing wall when the switch arm is aligned with theaxis of the housing wall seat, a compression spring having `one endsea-ted against the rear wall of the housing in axial alignnient with.said front wall seat having its other end seated against an axialportion of the switch arm inwardly-spaced from the seat thereof, wherebythe spring will yieldingly maintain the switch `arm either in a positionof coaxial alignment with the axis of the wall seat or in a relativelytilted position with respect to the wall seat axis, the front wall andswitch arm head having cooperating contact areas that are engaged in oneof said switch arm positions, said front wall having opposite fulcrumshoulder portions adjacent opposite inner marginal edges of therecesses, and cooperating shoulder portions on the switch Iarm forengagement with the wall shoulder portions under 'tilting movements ofthe switch arm, the said shoulder portions of the switch arm beinginwardly-spaced from the cooperating shoulder portions of the housingwall when the seat portions of the arm are seated against the seatportions of the wall.

4. In a switch of the class described, a switch housing having spacedfront and rear walls, the front wall being provided with a switcharm-receiving aperture and dening inwardly-facing seat portions adjacentopposite marginal portions of the aperture, said switch arm workingthrough said aperture with clearance for limited rocking movements in aplane intersecting the center of the aperture and having an expandedhead portion providing a seat -for engagement with the seat portions ofthe 'front housing wall when the switch arm is approximatelyperpendicular to the outer surface of the front wall, and a compressionspring having one end seated against the rear Wall Iof the housing at apoint inwardly-spaced from the inner end of the switch arm but in axialalignment with the switch arm when the latter is approximatelyperpendicular rto the outer surface of the front wall and having i-tsother end anchored to the inn-er end of said switch arm, whereby thespring will yieldingly maintain the switch arm Ieither in a seatedposition approximately 6 perpendicular to the outer face of the frontwall or in a relatively tilted position with respect to the outersurface of the front wall, the front wall and switch arm havingcooper-ating contact areas that are engaged in one of said switch armpositions, said front wall being provided with an annular fulcrumshoulder portion concentric with :and inwardly-spaced from and ofgreater diameter than the wall seat, and a cooperating fulcrum shoulderon the switch arm for fulcrum engagement with the wall shoulder undertilting movevments of the switch arm, the said annular fulcru-m shoulderportion of the switch arm being 4inwardly-spaced from the cooperatingshoulder of the housing wall when the switch .arm is aligned with theaxis of the aperture.

LESTER J. KARL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date '1,216,553 Dolan Feb. 20, 19171,809,527 Pate June 9, 1931 2,521,489 Sorensen Sept. 5, 1950 FOREIGNPATENTS Number Country Date 267,674 Great Britain Mar. 24, 1927

